like the one about whom God Almighty has said: ﴿أَفَمَنْ زُيِّنَ لَهُ سُوءُ عَمَلِهِ فَرَآهُ حَسَنًا﴾[1]; “Does someone whose badness of deed was made fair-seeming to him considers it good.” The reason for this great failure and mistake is the existence of factors in the human being’s self that obstruct him from achieving cognition despite observing; like curtains placed before his eyes that obstruct him from seeing things; as God Almighty has said about disbelievers: ﴿الَّذِينَ كَانَتْ أَعْيُنُهُمْ فِي غِطَاءٍ عَنْ ذِكْرِي وَكَانُوا لَا يَسْتَطِيعُونَ سَمْعًا﴾[2]; “Those whose eyes were veiled against the remembrance of Me and were not able to hear,” and also has said: ﴿وَجَعَلْنَا مِنْ بَيْنِ أَيْدِيهِمْ سَدًّا وَمِنْ خَلْفِهِمْ سَدًّا فَأَغْشَيْنَاهُمْ فَهُمْ لَا يُبْصِرُونَ﴾[3]; “And We have set a barrier in front of them and a barrier behind them, so We have covered them, therefore they cannot see.” These ominous and dangerous factors are called “impediments to cognition”. Therefore, the intellect, although it requires cognition, achieves it if there is no impediment in its way, and if there is an impediment in its way, then it is not capable of it. For this reason, knowing the impediments to cognition and removing them are introductions to cognition and, accordingly, necessary.

The most important impediments to cognition are the following[4]:

1. Ignorance

Ignorance, in the sense of lack of knowledge, is the most important impediment, but rather their origin; because its relation to cognition is like the relation of something to its opposite, and there is no impediment unless it has arisen from it; as God Almighty has said: ﴿كَذَلِكَ يَطْبَعُ اللَّهُ عَلَى قُلُوبِ الَّذِينَ لَا يَعْلَمُونَ﴾[5]; “In this way God seals the intellect of those who have no knowledge.”

[Necessity of knowing concepts and their examples]

It is clear that the intellect needs information to know an unknown thing so that it may know it by combining them;